As progress continues on this portrait, I finished the grisaille and experimented for about 10 minutes with skin tones to decide whether to use soft muted colors or the rich colorist approach to capture her lovely skin tone. I've decided to go soft because it more accurately captures the sheen of her skin which is smooth and creamy without being too shiny.
Once I established the appropriate color intensity, I modeled the forehead to study the range of skin tones from peach, reds, pinks, purples, greens, grey and yellows (blues don't show up until I moved down to the eye area). Then, I used what I had discovered about her skin to carry the same family across related areas of the face ... always looking for the lit/shadow/reflected light relationships.
By focusing on the rounding of the cheeks and skin below the eyes, I'm able to maintain the look of a genuine smile.
Until today, the sitter and I had not decided which shirt would work best so I painted the open collar area in a way that will allow us to add either shirt during the next sitting. The next sitting will also focus on glazing her eyes and adding "light" to them because she twinkles when she smiles.
The next sitting is scheduled for the end of August. So, look forward to the conclusion of this story then.